Braid covered electric cord and method of making such a cord



Oct. 15, 1940. w. 'r. .BARRANS 2,217,832

' BRAID COVERED ELECTRIC com) AND METHOD 0! IIAKIIIG SUCH A conn Filed larch 5, 1939 W VEN 0 W 7'. BARRANS ATTORN Y Patented 0a. 15, 1940 UNITED "STATES BBATD COVERED nmo'rnloconn AND METHOD OF MAKING SUCH A William T. Barrans, Towson, MIL, alsignor to Western Electric Company, Incorporated, New York, N. Y;, a corporation of New York Application March a. 19mm No. 259.507

12 Claims.

This invention relates to a braid covered electric cord and method of making such a cord and more particularly to a coiled extensible and retractile cord and method of making such a cord.

Objects of the invention are to provide a cord and method of making a cord having a high retractllity.

In accordance with one embodiment of the invention a covering of braided strands is applied to a helically coiled retractile electric cord and the strands passing spirally around the cord. in one direction have a higher tension applied thereto than the strands passing spirally around the cord in the opposite direction to increase the tendency of the cord to retract when extended.

A complete understanding of the invention may be had by reference to the following de-, scription' taken in conjunction with the accompanying drawing, in which Fig. l is a front elevation of a machine by means of which the invention may be practiced;

Fig. 21s a plan view taken on line 22 of Fig. 1;

Fig. 3 is a detail view" of a portion of a cord being made by the process of this invention,

and.

Fig. 4 is a'view similar to that of Fig." 3 show- The details 01' this machine are more fully disclosed in the patent to Miller, No. 1,602,442, of October 12,1926, and only such features or modifications as are necessary to practice the presentinvention will be disclosed herein.

Referring to Fig. 1, a frame 8 is shown havinga braider headwhich carries a series of oops I of yarn, or other suitable braiding material,

rotating in a counterclockwisedirection and a second series of cops 8 which rotate in a clockwise direction as viewed from above. The braiding is applied to a group of three conductors 9, forming a cord II, which is drawn through the machine by a rotating axial delivery capstan II. The capstan is rotated by a shaft l3 connected to a shaft it through a chain IS. The shaft It drives a pair of tension rolls it, which feed elastic members I! into the cord. The speed of the shafts II and It are so correlated as to produces tension 0! approximately 180% in the elastic members II. The elastic members under-- lie the braid and are fed as a group to one side end I! of the braiding head and the capstan. The tension in the elastic members gives the cord a tendency to form a helicalcoil. In forming a helical coil it is evidentthat there is a tendency for the braid in the outer portion of a 5 convolution to be stretched and for the braid on the inner portion of a convolution to be compressed. In addition to this there is a twisting action on the braid as the coil forms a helix.

This twisting action causes the successive con- In volutions of the coil to lie closely together. This latter tendency may be considerably enhanced by either applyingya twist to the cord as the braiding is applied or by applying a different tension to the yarns of one series of cops than 15 is applied to. the other.

In accordance with the first method the elastic elements are applied to'the cord. from the capstan and the cord 'is rotated 180- between the point of application 'of the braid and the g capstanwln this connection it may be noted that the elastic elements will of their own accord orientate themselves so as to lie .adjacent the capstan when they reach the capstan; Re-

- terring. ior instance, to Fig. .2 showing a plan 25 view of the upper stationary portion ll of the braider head, this portion of the head is pro-. vided with a cross-piece i9 having triangularly spaced guides for the conductors s of the cord and the elastic elements H are guided between 0 two projections II on the cross-piece.- In 'this figure the elastic elements II are shown rotated 180 .from the portion 01 the cord when it reaches the capstan. When a coil is made having a right hand pitch-the cord is twisted between the guides and'the capstan so that the elastic elements will be revolved clockwise 180, as viewed from above in Fig. 4, when the cord reaches the capstan. Oncqthe twist in the cord is started this way it will continue to twist in the same di- 40 rection. When it is desired to make a cord with a left-hand pitchthe twist in the cord would be started in the opposite direction. This rotation or twist in the cord between the point of ap cation of the braid and the capstan results in the 45 strands from the oops .I being incorporated in the braid in shorter length than the strands. from the cops l in a right hand pitch cord and increases .the tendency !or the cord to retract, or in other words, for the convolutions to come so closely together after the cord has been stretched.

A'similar result may be obtained by feeding the elastic elements to the cord on the side adjacent the capstan and applying a different tension to the two series or yarns. For this pnrls pose the cross-piece i9 would be rotated 180 from the position shown in Fig. 2, and for malt-,-

ing a retractile cord of right hand pitch a tension 01' four ounces would be applied to the yarns from the series of oops I rotating in a counterclockwise direction, and a tension of eight ounces would be applied to the yarns from the series of cops 8 rotating in a clockwise direction as viewed fromabove in Fig. 1. In this manner the yarns from the cops 8 will be incorporated in the braid in shorter lengths than the yarns from the oops I. For a cord of left hand pitch the tensions would of course be reversed. An extensible retractile cord made in this manner has a much higher tendency to resume a closely coiled helical form than a cord in which the braid is untwisted or equally tensioned.

It will be understood that the tensions and other specific features disclosed are merely illustrative and that many changes and modifications may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. A method of making a braided cord which comprises imparting a higher tension to the braid strands going in one direction around the cord than to m braid strands going in the other direction to incorporate the differently tensioned strands in the braid in different lengths.

2. A method of making a braided helically coiled cord which comprises unequally tensioning the strands of the braid so as to cause a tendency for the cord to assume a closely coiled form.

3. A method of making a braided cord which comprises vapplying a covering of braided strands to the cord, taking up the cordon a cylindrical take-up member, and causing the cord to twist between the point of application of the braid and the take-up device to apply unequal tensions to the braided strands.

4. A method of making a braided cord whic comprises applying a covering of braided strands to the cord, incorporating an elastic element in one side of the cord, taking up the braided cord, and causing the cord to twist between the braiding point and the take-up point.

5. A method of making a braided cord which comprises applying braided oppositely spiralled strands to the cord, and tensioning the strands going in one direction to a greater degree than the strands going in the other direction to provide an unbalanced tension in the strands.

6. A method of making a braided cord which comprises applying braided oppositely spiralled strands to the cord, tensioning the strands going in one direction to a greater degree than the strands going in the other direction, and incorporating an elastic element in one side of the cord.

7. A retractile cord having a covering of sets of braided strands the differentsets being unequally tensioned to cause the cord to coil closely.

8. A-retractile cord having an elastic element incorporated in one side thereof tending to cause the cord to coil and a covering of sets of braided strands the difierent sets being unequally tensioned to increase its tendency to retract.

9. A helically coiled retractile cord comprising a flexible conductor, and a covering of braided strands passing spirally in opposite directions around said conductor, the strands going in one direction being of greater length than the strands going in the other direction.

10. A helically coiled retractile cord comprising a flexible conductor, a covering of braided strands passing spirally in opposite directions around said conductor; the strands going in one direction having a higher tension applied thereto than the strands going in the other direction to increase its retractility, and an elastic element incorporated in one side of the cord to cause it to coil.

11. A helically coiled cord comprising a flexible conductor covered with strand material passing around the cord in opposite directions, the tension in the strands going in one direction being unbalanced with respect to the tension in the strands going in the opposite direction to aid in retracting the cord when extended.

12. A helically coiled cord comprising a flexible conductor covered with strand material in which the tension in the strands is unbalanced to aid in retracting the cord when extended, and a flexible element incorporated in one side of the cord.

WILLIAM T. BARRANS. 

